August 10, 2015

Photo: NASA TV

Two Russian Cosmonauts ventured outside the modules of the International Space Station on Monday to complete a long list of small tasks on the exterior of the orbiting complex in the only planned Russian spacewalk of the year.

Gennady Padalka and Mikhail Kornienko were facing a list of rather mundane tasks as far as spacewalks go, but nevertheless, they had a busy schedule laid out for their EVA. Racing through their tasks, the two spacewalkers finished all objectives in an excursion lasting five hours and 31 minutes.

Over the course of the EVA, the two Cosmonauts assumed many roles - from window cleaners over engineers and electricians to photographers. They removed propellant residuals from a window on the Russian segment, installed protective equipment on communications antennas, replaced an old antenna with a spare and reconfigured a series of experiment payloads located on the exterior of the Russian Segment.

Russian EVA-41 was the fourth spacewalk performed in 2015 and the only planned Russian EVA with two more USOS spacewalks scheduled before the end of the year. For the two Cosmonauts, the EVA was not their first walk in space. Mikhail Kornienko has performed one prior EVA and is currently in the middle of a one-year mission to ISS. His EVA colleague Gennady Padalka had nine EVAs under his belt prior to Monday's spacewalk, performed as part of his previous four long-duration missions to the Mir Space Station and ISS, holding the record for most time spent in space.

Working through the usual several-week preparation process, the two crew members readied their suits, configured the Pirs airlock and went through multiple reviews of EVA procedures leading up to EVA day on Monday. Given the late start of the EVA, the Cosmonauts were able to sleep in before pressing into their EVA preparations. They activated the two Orlan space suits and configured the Pirs module for its role as airlock before going through communication checks through the suits and ensured all consumables within the Orlans were at the expected levels.

Oleg Kononenko, the third Russian crew member on ISS, was in charge of closing the hatch to the Pirs airlock with the other two Cosmonauts inside. As part of Russian EVAs, the PKhO transfer compartment - joining the Pirs airlock to the Zvezda, Zarya and Poisk modules, is normally closed for the entire duration of the spacewalk, requiring crew members of Soyuz craft docked to Poisk to be isolated. Because the only crew member of that Soyuz who was not involved in the EVA was Scott Kelly, teams decided to keep the PKhO open until the late stages of the EVA, shortening the time spent in isolation for Scott Kelly to around two hours. PKhO acts as a backup airlock and has to be sealed off to be available in case Pirs can not be repressurized for some reason.

With the crew inside the suits and only Pirs sealed off, teams went through a series of leak checks on both, the two Orlan suits and the airlock itself. Next was the half-hour pre-breathe of pure oxygen to remove nitrogen from the blood, preventing decompression sickness given the reduced pressure inside the Russian suits. When all checks had shown good results, the crew members received the go-ahead for the depressurization of the Pirs module that was completed swiftly and with no issues, including a repetition of leak checks on Pirs and the suits. When Pirs had reached vacuum, the spacewalkers switched their suits to internal power and cooling, allowing them to remove the electrical and fluid umbilicals. Mission Control Moscow gave the two crew members a GO to open the hatch.

The official start of the spacewalk was marked at 14:20 UTC when Mikhail Kornienko opened up the hatch of the Pirs module to get started with a long task list, the first of which was the prescribed installation of a ring in the hatchway to protect the hatch seal during the EVA.

Photo: NASA TV

Kornienko was first to exit the airlock, climbing out onto the EVA ladder where he set up his safety tethers before receiving a Crew Lock Bag from Gennady Padalka containing the equipment needed for the first half of the EVA - window cleaning equipment, fastener kits for antennas and sampling hardware. Padalka then exited the airlock himself and the two crew members began the translation from Pirs down towards the PKhO and aft to the Zvezda Service Module.

Photo: NASA TV

Window 2 Cleaning (above), WAL Antenna Covers (below)

Photo: NASA TV

The first task at Zvezda was the installation of a gap spanner or soft handrail between hand rails 2511 and 2512 for use in future EVAs to help in translation of crew members around the Zvezda Service Module. They made quick work putting the gap spanner in place and continued their translation to a position near the Plane IV URM-D Universal Work Platform from where Mikhail Kornienko could access Window #2 of the Service Module.

Window #2 is one of the 23-centimeter windows of the Zvezda module and one of the two windows in the crew quarters of the module. Over the years, windows of ISS that do not have covers to protect them experience periodic showers of unburnt propellant residuals expelled by visiting vehicles when firing their thrusters in close proximity to ISS. All windows used for optical observations including those on the Cupola have shutters that are closed whenever a visiting vehicle arrives/leaves or any thrusters are used on ISS.

Making use of a specially fabricated tool, Mikhail Kornienko spent several minutes removing the contamination from the window pane with Oleg Kononenko having a watchful eye from inside ISS, approving Kornienko's cleaning job with a thumbs-up.

Departing Window #2, the Cosmonaut duo headed to the aft end of Zvezda where three WAL Proximity Communications Antenna Assemblies are located. Formerly used by the Automated Transfer Vehicle that is now retired, the antennas are being preserved for potential future use by visiting vehicles that need to transfer data to and from ISS such as video or relative GPS data. A known problem with the antennas are their covers that, in the past, have inadvertently become detached and floated away, leaving the antennas without thermal and MMOD protection. To overcome this issue, special fastener kits were fabricated to be installed over the antenna cover and secured on the antenna structure to firmly hold the cover in place.

Despite some initial trouble with the placement of the fastener, the two spacewalkers completed the task well ahead of schedule - putting in place three fastener kits on the aft WAL antennas. They then moved to hand rail 2525 where they used towels to wipe down their suits and gloves to remove any propellant residuals they may have picked up when working around the Russian thrusters in the aft section of Zvezda.

The two towels were thrown overboard as part of the standard procedure and the crew took a break to wait out orbital night.

When the sun was up again, Gennady Padalka spent several minutes collecting photos of the EXPOSE-R exposure experiment that facilitates a number of samples that are exposed to the space environment to study the response of different materials and organisms to the extreme thermal environment, ionizing radiation, microgravity and species such as atomic oxygen.

Mikhail Kornienko worked with the Obstanovka experiment, removing the ДП-ПМ experiment from the ПВК1 unit of the Obstanovka payload. Obstanovka (=Environment) features external hardware including a set of magnetometers, wave sensors, potential probes, plasma discharge stimulators, an electron spectrograph and other components to study space weather. Obstanovka examines electromagnetic fields and plasma-wave processes occurring in the ISS Near Surface Zone to reveal plasma component factors in near-Earth space. The ДП-ПМ experiment was located atop the payload monoblock to be exposed to space for a period of time before being returned to Earth for analysis.

EXPOSE-R Experiment Payload

Photo: NASA

Obstanovka

Image: NASA

The next task for the EVA duo was the collection of swab samples from three locations - an external radiator panel, a portion of the SM solar array and the vent port of the Elektron oxygen generation system that vents hydrogen into space as a byproduct of the generation of oxygen through the electrolysis of water.

The swab samples were collected using the Test Samplers that made appearances in almost all recent RSOS spacewalks. Samples collected from the various surfaces and areas are returned to Earth for laboratory analysis to point to any substances that may be accumulating on the windows (propellant residuals and other substances) or show any signs of corrosion on the window shell or even microbial activity. This study provides valuable engineering information, but is also of scientific value. A number of sampling activities were performed on recent Russian EVAs to provide data from several different window locations.

The two-man team then moved back to the Pirs airlock where they switched out equipment bags and headed off to the small diameter of Zvezda where another set of three WAL antennas is installed.

Photo: NASA TV

Image: NASA

WAL-4 and 5 received their fastener kits before the crew dedicated over an hour of their time to WAL-6 that was to be replaced in its entirety because it had lost its protective cover and was no longer working.

The spacewalkers collected photos of the configuration of WAL-6 and Kornienko went over to the FP-10 connector patch panel to disconnect the power and data cable, allowing Padalka to exercise his cable cutter to cut the cable of WAL-6 that was then removed and placed in a crew bag. WAL-6 was removed by Padalka and the duo started the installation of the new unit using a clamp to attach the new WAL-6 to hand rail 2233.

Photo: NASA TV

When unwinding the WAL-6 Cable, Padalka ran into some trouble because of a rubber band that prevented the cable from properly unwinding from the reel. Improvising with the cable cutter, Padalka and Kornienko successfully cut the band and were able to route the new cable along hand rails and cable clamps to the FP-10 patch panel. There, the connector was plugged into the 10-11 slot to conclude the task, allowing the crew to close out the patch panel and document the work site before moving back to Pirs to temp-stow the WAL-6 antenna and the equipment bag.

For the last task, the EVA duo translated up the Strela Boom to reach the Poisk Module where the БКДО Plume Impingement and Deposit Monitoring Experiment Unit resides. After pointing down towards the Pirs module for its first year of operation, the unit was re-oriented by 90 degrees to face Station-aft towards Zvezda. The system studies the plumes created by the thrusters of visiting vehicles and the Space Station itself to learn more about the impingement characteristics of the thruster plumes and processes causing the deposition of combustion products on the external hull of the space station.

The spacewalking Cosmonauts returned to Pirs after taking some time for photos and videos. At the airlock, Kornienko went back inside while Padalka positioned himself for the jettisoning of the removed WAL-6 antenna. No-longer-needed external equipment is oftentimes jettisoned into a retrograde trajectory for disposal on a safe departure path that rules out any re-contact with ISS.

Photo: NASA TV

Photo: NASA TV/ISS Twitter

With all tasks complete, the crew returned to Pirs, conducting a tool and equipment inventory before taking a few minutes to enjoy the view. After both crew members were back inside and their sublimators had been deactivated, Mission Control signaled the GO for the closure of the hatch which came at 19:51 UTC after an official EVA time of 5 hours and 31 minutes.

Pirs was repressurized and went through leak checks before the crew was allowed to get out of their suits and return to the Space Station along with Scott Kelly who spent only an hour inside Poisk in isolation. For the rest of the day, the EV crew will set up their suits for drying before heading into tool deconfiguration and suit maintenance on Tuesday.

Monday's EVA was the 188th spacewalk in support of ISS Assembly & Maintenance. It was the tenth EVA for Gennady Padalka whose total now stands at 38 hours and 37 minutes. For Mikhail Kornienko it was the second excursion into space for a career EVA time of 12 hours and 13 minutes.

Photo: NASA TV

Returning to ISS, the Russian crew members will be greeted by some fresh produce, harvested on Monday from the Veggie plant growth experiment to mark the first time space-grown lettuce was consumed by a crew in orbit. The three USOS crew members enjoyed some lettuce with olive oil and vinegar, but also saved some for the two spacewalkers who were hard at work when the lettuce was being harvested.

The next ISS EVA will come in the fall after the relocation of Pressurized Mating Adapter 3 from Node-3 to Node-2 in the ongoing effort of reconfiguring the Space Station for commercial crew vehicles.

Window Cleaners in Space - Russian EVA Duo ready for busy Spacewalk

August 10, 2015

Two Cosmonauts are set for a busy spacewalk on Monday to complete maintenance work on the exterior of the Russian Segment of the International Space Station. Veteran spacewalkers Gennady Padalka and Mikhail Kornienko are planned to venture outside at 14:14 UTC to work for about six and a half hours to install flexible hand rails, put in place fasteners on communications antennas, replace an old antenna used for rendezvous and dockings of Russian vehicles, clean windows on the Russian Service Module, retrieve an external experiment payload and conduct a detailed photographic survey of a number of locations on the Russian Segment.

Gennady Padalka, recently setting the record for the most time spent in space with over 800 days logged in orbit, is no stranger to spacewalking. On his previous flights to the Mir Space Station and three prior ISS missions, Padalka completed nine EVAs for a total of 33 hours and 6 minutes. Mikhail Kornienko, currently in the midst of a one-year deployment to the Space Station, can look back at one EVA lasting six hours and 43 minutes.

*File Image* - Photo: NASA

The
EVA duo began preparing for Russian EVA-41 in mid-July, setting up their
Orlan space suits, readying their tools and installing American EVA
equipment on the suits such as cameras and lights. They also spent time
studying their procedures and translation paths they will use as part of
the EVA. Putting on their Orlan suits, the two EV crew members
completed a series of checkouts on the suits and went through the usual
in-cabin exercises to check the suit fit and familiarize themselves with
the environment in their suits. Also in preparation for the EVA, the
Progress cargo craft currently docked to Pirs was activated and had its
hatch closed for the unlikely event of an emergency undocking required
while Pirs is sealed off for its role as airlock.

On Monday, the six crew members aboard ISS will part ways - Scott Kelly will
have to be isolated inside the Poisk Module with access to his Soyuz
spacecraft because the PKhO transfer compartment joining Poisk, Pirs,
Zarya and Zvezda will be sealed off as part of the EVA to serve as a
backup airlock.

The other crew members, Oleg Kononenko, Kimiya Yui and Kjell Lindgren will have access to all modules forward of the PKhO with access to their Soyuz TMA-17M. Oleg Kononenko will be in charge of hatch closures and leak checks on the PKhO while Padalka and Kornienko will ingress their space suits inside Pirs.

Photo: NASA

Suit checks will be completed by the duo as well as the usual EVA pre-breathe while PKhO leak checks are being performed. Next, the Pirs module will begin depressurization in a methodical fashion that includes a leak check of the module and suits.

When the module is fully depressurized, Mikhail Kornienko, serving as EV-2, will open the hatch of the Pirs Module and climb out onto the EVA ladder right in front of the hatch to set up shop, first configuring his tethers to make sure he is secured on the exterior of ISS.

While still inside Pirs, Padalka will retrieve EVA equipment to hand it out to Kornienko, specifically a Crew Lock Bag with the Test hardware, a series of bundled soft handrails, fastener kits and the necessary equipment for the window cleaning task. Padalka will then exit the airlock himself to join Kornienko on the outside. The duo will then start the translation from the EVA ladder to hand rail 2511, Plane IV of the Zvezda Service Module.

EVA-41 Work Zones

Image: Roscosmos/TsUP

Arriving at the work site, the EV crew will install a flexible hand rail between hand rails 2511 and 2512 for use in translations as part of future EVAs. The spacewalkers then translate over to the Plane IV URM-D Universal Work Platform to be able to access window #2 of the Russian Service Module, one of two 23-centimeter diameter windows of the module. They will spend about 15 minutes cleaning window #2 to remove propellant and combustion product residuals that are deposited on the windows and external panels of the Space Station when visiting vehicles fire their thrusters in close proximity to ISS.

From Window #2, the two spacewalkers will make their way aft to hand rail 2612 where they will part ways as Padalka translates to HR #2616 and Kornienko moves over to HR #2644. Working at Wireless Antenna Assembly 1 & 2, the two spacewalkers will install fastener kits on the antennas, a task taking just about five minutes before Kornienko moves on to Wireless Antenna Assembly 3 to install a fastener over there. These fasteners will prevent the antenna covers from inadvertently detaching themselves and floating off, leaving the antennas without thermal and MMOD protection, a problem that occurred in the past.

Meanwhile, Gennady Padalka translates to HR #2632 where he will wait for Kornienko to move to HR #2525. The duo will complete checks of their suits and wipe their gloves with towels to remove any contamination after working around the Russian thrusters where propellant residuals are deposited onto ISS hardware. The towels will be thrown overboard and the spacewalkers will move on - Gennady Padalka will go over to Universal Work Platform II to photograph the EXPOSE-R Payload that was installed back in 2014.

The EXPOSE payload platform was developed by the European Space Agency to conduct astrobiology studies by exposing samples and experiments to the space environment - mounting the platforms on the exterior of ISS for an extended period of time before retrieving them for return to Earth.

Image: NASA TV

SM Window Cleaning (above), WAL Fastener Kit Install (below)

Image: NASA TV

The effects of the space environment (increased UV exposure, cosmic radiation, microgravity, atomic oxygen, temperature variations) on organic matter and organisms have been heavily studied via space-based experiments and in ground-based laboratory simulations. These studies are performed to better understand the role of interstellar, cometary and planetary chemistry with respect to prebiotic molecules leading to the formation and evolution of life on Earth, also assessing the possibility of its distribution in space. EXPOSE experiments in the past exposed solid materials, gas mixtures, and biological samples to the space environment to simulate conditions on Mars and comets. The experiment module hosts four experiments – BIOMEX, BOSS, PSS and Biochip.

Mikhail Kornienko will make his way to HR #2521 to access the Obstanovka Experiment Module to remove the PBK-1 Unit from the monoblock and place it in his tool bag. Obstanovka (=Environment) features external hardware including a set of magnetometers, wave sensors, potential probes, plasma discharge stimulators, an electron spectrograph and other components to study space weather. Obstanovka examines electromagnetic fields and plasma-wave processes occurring in the ISS Near Surface Zone to reveal plasma component factors in near-Earth space.

Image: NASA TV

WAL-6 Work Site (above), Cable Routing (below)

Image: NASA TV

Working together, the EV crew will install another gap spanner or flexible handrail between HR #2414 and #2523 to help future EV crews translate around the Service Module. Finishing their work, the duo will move over to hand rail 2441 from where they can access an external radiator to collect swab samples from the SM solar array and radiator panel to undergo ground-based analysis to look at material deterioration in the space environment and possible microbial growth. Samples will also be collected near the exhaust port of the Elektron Oxygen Generator that vents Hydrogen, a byproduct in the electrolysis of water, into space.

Making their way back to Pirs, the spacewalkers will stow the tool bag inside the airlock and retrieve a tool kit containing another set of WAL antenna covers and EVA cutters. Padalka and Kornienko will translate to HR #2312 to put in place the fastener kit on Wireless Antenna Assembly 5, done by Padalka, before moving over to HR #2241 to allow Kornienko to install the fastener on WAL #4. Next, Padalka moves to HR #2225 to access Wireless Antenna Assembly 6 that will be removed and replaced, but only after Mikhail Kornienko moves over to the FP10 Connector Patch Panel to demate the electrical and data connector to WAL-6 to make it safe for Padalka to remove the antenna system.

Making use of the EVA cutter, Padalka will cut the WAL 6 cable and remove it from its cable clamp so that Kornienko can coil up the cable and put it in the temp-stowed tool carrier. The old WAL 6 antenna will be removed with its bracket from the handrail (2233) to make room for the new unit that will be attached by Gennady Padalka who will hand the new WAL 6 cable to Kornienko to be routed back to FP10, providing connectivity to the newly installed antenna. Routing the cable, Kornienko will use cable clamps on hand rails 2233, 2242 and the patch panel where the connector will be plugged into the 10-11 slot.

The new FP10 configuration will be documented in photos by Kornienko before the panel is closed up again. Overall, the WAL 6 task is planned to take around 70 minutes to complete.

The two spacewalkers will return to the EVA ladder on Pirs from where Kornienko will stow the tool carrier inside the airlock and Padalka can get into a good position to jettison the removed WAL 6 antenna and bracket assembly to float away from ISS and eventually re-enter the atmosphere. To finish the EVA, the crew members will translate around Pirs and up the Strela Boom that currently acts as a bridge between Pirs and Poisk.

At Poisk, the spacewalkers will go to the БКДО Plume Impingement Experiment Unit and re-position it for future data collection. БКДО is pointing down to the PKhO looking at the Pirs module to study the plumes created by the thrusters of visiting vehicles and the Space Station itself to learn more about the impingement characteristics of the thruster plumes and processes causing the deposition of combustion products on the external hull of the space station.

Image: NASA

The new orientation of the system will be documented and the EV crew will make their way back down to Pirs for ingress.

Gennady Padalka will be first to climb back into the airlock followed by Mikhail Kornienko who will close the hatch to mark the conclusion of Russian EVA-41, expected around 20:48 UTC. The Pirs hatch will be locked to enable teams to repressurize the module after an EVA that, from a procedures point of view, presents only very few challenges.

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